A conventional agitation mixing apparatus for agitating and mixing a fluid is disclosed in Patent Literatures 1 and 2. The agitation mixing apparatus includes, in a cylindrical casing, a helical vane connected to a vibration source. Plural kinds of fluids are supplied into the casing, and the fluids are agitated and mixed by means of the vane which vibrates in the axial direction. Thus, the agitation mixing apparatus as described above can be used for, for example, production of an emulsion, agitators for use in apparatuses for performing pH adjustment and/or causing chemical reaction such as oxidation-reduction reaction, and agitators for use in extractors.